Techniques disclosed in recent years include techniques in which a user operates a mobile terminal with respect to an image displayed on a display so that the user obtains information relevant to the image.
For example, Patent Literature 1 discloses an information providing system in which pointing is carried out from a mobile information terminal with respect to a video image displayed on a display so that information relevant to the video image located at a pointing location is provided to the mobile information terminal. According to the information providing system, a superimposed video image, which has been obtained by superimposing an information video image on a captured video image captured by a video camera, is displayed on a display, and information concerning an information video image displayed at the pointing location is transmitted to the mobile information terminal.
Patent Literature 2 discloses an information distributing device that displays, on a display, display information having a hierarchical structure and then transmits, to a mobile communication device, transmission information based on an image and a distance which have been received, the image being an image which has been captured by the mobile communication device and which corresponds to the display information, and the distance being a distance between the mobile communication device and the display, which distance has been calculated from results of a focusing operation during capturing of the image.
Patent Literature 3 discloses a method of causing a mobile device, which can read a tag ID, and a screen to interact with each other. According to the method, a service UI is projected with use of a projector onto a tag matrix provided on a screen, and then the mobile device reads a tag ID(s) of one or more tags of the tag matrix and then transmits, to a server, the tag ID(s) thus read. Then, a server updates service data according to the tag ID(s) obtained, and then transmits the service data to the projector and to the mobile device. Then, the projector updates the service UI according to the service data obtained, and the mobile device displays a UI which is based on the service data obtained.